If I was a bit snarky, I would say confrontation is the replacement to the dying CW as a reason to be part of a clan. CW being the only way to get ura is ultra competitive with a serious lack of new blood and you can’t expect to win without at least legendaries, and you will be facing fused relics most of the time.
Confrontation is still competitive but way more lenient (it sadly lacks ranks that would help it become a real competitive mode). Players of all skills do it and the max ps makes sure you won’t get destroyed by builds you could only dream of.
You will get way more confrontation points from CC matches than normal PVP, so there’s that for incentive.
And the 4v4 format is appealing for those that want a no-bot competitive mode that’s not as expensive or intense as CW. The PS limit makes it more about skills than wallet, and newer players aren’t at as much of a disadvantage.
Having said that, some of the most popular CC builds are relatively expensive. Doesn’t mean you can’t play it though, just because you don’t have cyclones and gerridas.
Activity points are just something you need to get a bare minimum of in order to get the badges from the challenges your clan completes. The confrontation points are what raise the rank of your clan to unlock more challenges.
There are lots of clans that never play CW, and exist just to complete clan challenges together. People in those clans may want to play CC to increase the ranking of their clan to unlock more challenges.